Thermal printing, because of its simplicity and low-noise level, has potentially many advantages over existing printing methods as a low-cost and relatively noise-free method of printing and generating characters. However, the acceptance of thermal printing has not been rapid because of the need for special paper and the nonpermanence of the heat-sensitive paper that is required for thermal printing.
Therefore, a need exists for a thermally activated ink, transfer ribbon and printing method for generating printed characters on ordinary paper. Present commercialized thermal printing can produce only blue or blue-black dye images of low to moderate darkness and opacity. Therefore, a need also exists for a thermal printing ink and method for producing black images having improved contrast and readability qualities. A need further exists for a thermally activated ink and method for producing high-quality, non-smudgeable, permanent characters on ordinary paper which characters are flexible and elastic to avoid flaking.